Identification of novel factors associated with inappropriate treatment of asymptomatic bacteriuria in acute and long-term care

Background: Chart reviews often fall short of determining what drove antibiotic treatment of asymptomatic bacteriuria (ASB). To overcome this shortcoming, we searched providers' free-text for documentation of their decision-making and for misleading signs and symptoms that may trigger unnecessary treatment of ASB.

Methods: We reviewed a random sample of 10 positive urine cultures per month, per facility, from patients in acute or long-term care wards at 8 Veterans Affairs facilities. Cultures were classified as urinary tract infection (UTI) or ASB, and as treated or untreated. Charts were searched for 13 potentially misleading symptoms, and free-text documentation of providers' decision-making was classified into 5 categories. We used generalized estimating equations logistic regression to identify factors associated with ASB treatment.

Results: One hundred fifty-eight (27.5%) of 575 ASB cases were inappropriately treated with antibiotics. Significant factors associated with inappropriate treatment included: abdominal pain, falls, decreased urine output, urine characteristics, abnormal vital signs, laboratory values, and voiding issues. Providers prescribed an average of 1.4 antimicrobials to patients with ASB, with cephalosporins (41%) and fluoroquinolones (21%) being the most common classes prescribed.

Conclusions: Chart reviews of providers' decision-making highlighted new factors associated with inappropriate ASB treatment. These findings can help design antibiotic stewardship interventions for ASB.